Multitude existing engines, such as aircraft engines, and also including automobile, marine, industrial and other engines, require an igniter for initiating and maintaining combustion in the engine. An igniter for the combustor of a gas turbine engine permits the production of an electrical spark across a gap formed between oppositely charged electrodes. The spark so produced is effective for igniting a combustible fuel-air mixture within the combustor.
Igniters in the existing art typically use one electrode as a source for the spark. This does not permit a second source to be connected directly to the igniter. In some existing art, a single electrode source for the spark is split internally to provide multiple sparking points. This existing art requires ground electrodes. One example of an existing igniter is that disclosed in U.S. Pat. No. 4,275,559 wherein an igniter is affixed to a combustion chamber with the electrodes extending a short distance to an ignition position in the combustor. This device includes spring retention of the electrodes in the ignition position. The spring permits the electrodes to retract from the combustor in the presence of high pressure within the combustor, as occurs once ignition is attained.
In order to provide redundancy and enhance safety, existing systems often require the use of a second igniter. However, use of a second igniter can significantly impact cost, weight and complexity.
It would be desirable to be able to increase system reliability without requiring a second, or additional, igniter.